Process of treating ores.



' No. 880,752. PAT-ENTED MAR. a, 1908.

J. PATTBN & 0. R. BARNETT.

PROCESS OF TREATING ORES.

APPLICATION FILED OUT. 31. 1907.

Inwwkws WH'MQMQQ j w 7,6441% I alt Dome? JOHN PATTEN AND CHARLES R.BARNETT, OF BALTIMORE,'MARYLAND.

PROCESS OF TREATING ORES.

Specification of Letters Patent.

. Patented March's, 1908.

Application filed October 31- 1907- Sei-ial No. 400.135.

To all whom it may concern:

Be it known that We,'JOHN PATTEN and CHARLES R. BARNETT, of Baltimore,in the county of Baltimore and State of Maryland, have invented certainnew and useful Improvements in Processes for Treating Ores; and we dohereby declare the following to be a full, clear, and exact descriptionof the invention, such as will enable others skilled in the art to whichit appertains to make and use the same.

This invention relates to processes for treating ores, and moreparticularly to an improved process for se arating sulfid of antimonyfrom antimonia ores;

The object of our invention is to rovide a practical process forleaching the su d of antimony (stibnite) from what is known as low gradeores and recovering the sulfid of antimony in the form of a hydratedsulfid of antimony which will afterwards be put through other processesfor drying it and producing the metallic antimon 7 Experience has. shownthat antimony is a more difiicult metal to reduce from its ores thanmost other base metals and the present methods of smelting it are notadapted for working low grade ores; that is, ore containing fromtwenty-five to thirty per cent. antimony is not profitable to smelt bythe 'gh grade ores containing over fifty per cent. antimony is soughtand when it lsmixed with silicious matter the stibnite is separated thelumps of by liquation. That is to say; ore are heated to a dull red heatwhich melts the stibnite and causes it to run into another vessel,producing what is known as crude antimony, which is almost pure sulfidof antimony,.and this is then smelted by the usual methods. An orecontaining from five to twenty per cent. antimony distributed throughthe ore. cannot be separated in that way. If the ore be pulverized andheated,

the stibnite and silicious matter will fusetogether and no sulfid,ofantimony would run off. We therefore propose to dissolve the stlbniteout of theore and then preci itate it as a stibnite or sulfid ofantimony su ciently pure to smelt for the recovery of'the metal.

In carrying out our process we use a sulfid of one of the alkali metalsor earths, preferably, the sulfid of sodium, though the sulfid,

of potassium will answer, but the mono-sulfid rocess now in general use,and consequently before it is filtered. i Our process can bebetter-understoodf by' referri'n to the accom 'anying'drawing inwhichrepresents a a clllatillg P collecting tan provided with an agitator A:operated 'by of calcium is not sufficiently soluble for use in ourrocess. of calcium but as stated above we prefer sodium sulfid and tothis we will referin describing the process.

In carrying out our process, we use continuously a sulfid of sodasolution which passes through a cycle of 0 erations without eingdecomposed. We fact that antimony sulfid is more soluble in a hotsolution of sodium sulfid than it is in a cold solution, so we pass acurrent of hot sodium sulfid through a tank containing crushedantimonial ore which saturates the solution with sulfid of antimony.Sometimes arsenic will be present and will be extracted in the same wayand sometimes the solution will take up a little'silicious matter. Weseparate these from the solution by feeding a little milk of lime intothe hot liquor as it leaves the digesting pan. The lime compounds forminsoluble precipitates which either settle to the bottom or are filteredout. Thehot liquor is then cooled epend upon the We can use thepenta-sulfid precipitates a large part 0 the sulfid of I antimony in'the form of a hydrated sulfid of antimony, which is either allowed tosettle to the bottom of the tank or is filtered out, and

the effluent liquor returned to the digesting vat to be sued over againas previously described. The hot liquor going one way passes through aheat exchanger in which the cold liquor is traveling the otherway,thereby cold liquor is traveling; the other way,thereby heating thecoldliquor and'coolingthe hot by a simple exohan e ofheat. is thencooled furt er igesting tank} The'hot liquor 1 (by circulating water) 7the ear A and said'tankis'rprovide'd witlia man ole A for-charging itvwith crushed'jore; 1 and with the valve A for dumpingout the waste,afterv the antimonyhas been extracted-. A filtering tube A is interposedi'nthe-upper verportion-Tofthe tank to prevent the fpu 1zed ore frompassing out with the hot liquor.

Theta-11k Bis provided with a' dumping'valwe' B, and filtering tube BThe heat exchanger C is provided with the heat exchanger coil G acooling coil O and distributing trough C The pump D and filter press Eare of usual construction.

The operation is as follows: After the apparatus has been charged withore and so ium sulfid as described, the pump D causes the liquor tocirculate in the direction indicated by the arrows. The liquor entersthe bottonr'of the digester A through the pipe A and percolatesthroughthe pulverized ore, which 1s occasionally stirred by the agitator Adissolving as much antimony sulfid as it is capable of holding insolution at that temperature, and it is kept hot by the steam jacket AIt then passes through the filter tube A and out through the pipe B intothe liming tank B and at the same time, a pump Gr feeds a small quantityof lime water or milk of lime into said tank B, from a tank G. Causticlime does not decompose or react with a solution of sodium sulfid andantimony sulfid, dissolved in same, but it will react with a great manyimpurities forming insoluble precipitates which are precipitated in thetank B, and occasionally blown out throu h the valve B Sometimes theyare floccu cut and do not settle readily, and must be filtered out bythe filtering tube B or any other form of filter. Sometimes the limewill be fed in with the ore and the insoluble lime compounds formeddumped out with the waste. The urified hot saturated liquid passes out tough the pipe 64 into the heat exchanger 0, first enterin thedistributing trou h C and trickles own the outside of the eat exchangercoil C This coil contains the cold liquor running in the oppositedirection, so that the saturated liquor is cooled as it descends, at thesame time preci itating a part of the antimony sulfid whic is a looseflocculent precipitate which washes down with the li uor. After theliquor leaves the coil 0 alt ough it has been cooled considerably it isstill warm and is further cooled by the coil C which. has cooling watercirculating through it. The cold saturated liquor; II11X 6(l with theprecipitate runs to the bottom of the tank C and into the pum D and isforced through the pipe D into t e filter E, which is of ordinaryconstruction. Theclearliquorwhichemerges from the filter passes throu hthe pipe E into the lower end of the coi C then down throu h the pipe 0after having been heate by the heat exchanger.

sulfid is dumped to the tank below, afterwhich it will be dried forfurther use. After the antimony sulfid is extracted from the digester,the valve A will be opened (after having removed the solution) and thewaste from the ore dumped out. A new charge of ore will then be insertedand the antimony extracted as previously described. When we are workingon a large scale, we will employ several of these digesters and workthem 1n tandem in such a way that the weak liquor will first enter thetank from which the most of the antimony has been extracted, then travelto the next and'end with fresh ore. The different digesters will beprovided with pipes, valves &c., so that one of.

them can be cut out and recharged without interfering with the operationof the others.

Having fully described our invention what we claim as new and desire tosecure by Letters-Patent, is,

1. A process for separating antimony sulfid from antimonial ores,consisting in circulating a solution of sodium sulfid through hot ores,then cooling the-solution, causing a portion of the dissolved antimonialsulfid to precipitate, then separating the recipitated antimonial sulfidfrom the so ution, then heating the solution again running it throughthe hot ore again, substantially as described.

2. A process for separating the sulfid of antimony from the antimonialores with a solvent sulfid solution consistin in alternately'heating thesolution, bringln the hot solutlon in contact with the crus ed ore,cooling the saturated solution to precipitate a part of the dissolvedantimony, separating the preci itant, heating the clarified solutionagain an using it over again.

3. A process for separating the sulfid of antimony from the antimonialores with a solvent sulfid solution consistin in alternately heating thesolution, bringing the hot solution in contact with the crushed oreaddmonial sulfi then filtering to recover the antimonial sulfid, andthen subjecting ore to the resultant solution in the presence of heat.

5. A process for separating antimonial sulfid from antimonial ores,consisting in assing a solvent sulfid solution through sai ores in theresence of heat, subjecting the resultant so ution to a cooling mediumconsisting of a previously cooled portion of solution from which theantimonial sulfid has been removed.

6. A process for separating antimonial sulfid from antimonial ores,consisting in treata mass of such ore with a solvent sulfid so ution,filtering the resultant solution, utilizing the filtered solution toabsorb heat from that portion of the solution assing from the mass ofore, and then con noting the solution thus heated to the mass of ore.

7. A process for separating antimonial sulfid from antimonial ore,consisting in subjecting a mass of such ore to the actlon of a solventsulfid solution in the presence of heat, cooling the resultant solution,filtering the solution now containing antimonial precipitate, andsubsequently heating the resultant solution, and conducting it to theore.

8. A process for separating antimonial sulfid from antimonial ore,consisting in passing a solvent sulfid solution through such ore, in theresence of heat, subjecting the resultant so ution to a liming action,cooling the solution, filtering the solution, now containingantimonial'precipitate, and returning the resultant solution to the ore.

9. A process for separating antimonial sulfid from antim'onial ores,consisting in passing a solventsulfid solution through such ore,

' in the resence of heat, subjecting the resultant so ution to a coolingaction, filtering the solution, utilizing the resultant solution forcooling solution flowing from the ore and sulfid from antimonial ores,consisting in sub jecting a niass of such ore to the action of a solventsulfid solution in the presence of heat, cooling the resultant solution,and then filtering the cooled solution.

11. A process for separating antimonial sulfid from antimonial ore,consisting in assing through a mass of such ore, a so vent sulfidsolution in the presence of heat, agitatin the mass of ore, subjectingthe resultant so ution to a liming action and then cooling it, and thenfiltering the cooled solution to recover the antimonial sulfidprecipitate.

12. A process for separating antimonial sulfid from antimonial ore,consistin in passing a solvent sulfid solution throug a mass of such orein the presence of heat, alternately cooling and heating the solutionpassing from the ore, filtering the cooled solution, and returning theheated solution to the ore.

In testimony Whereol', We have signed this specification in the presenceof two subscribing witnesses.

' JOHN PATTEN. C. R. BARNETT. Witnesses:

LEWIS N. HOPKINS Jr., Jos. T. BYRNE.

